(function () {
    var designwidth = 750;
    var fontsize = 100;

    function resize() {
        var width = document.documentElement.clientWidth;
        var size = width / designwidth * fontsize;
        var html = document.querySelector('html');
        html.style.fontSize = size + "px";
    }
    resize();
    window.onresize = resize;
    
})(window, document);
